In an accident, nerve damage can result from injuries to the central nervous system, i.e., the brain and the spinal cord, or to the peripheral nerves. In either case, nerve damage can affect your ability to move.
Doctors use several different tests to diagnose nerve damage. These tests measure which of your nerves the injury affects and the extent of the damage.
Needle electromyography
Your muscles move when your peripheral nerves send signals to them from your brain in the form of electrical impulses. A needle EMG measures your muscles’ electrical activity. According to the Hospital of Special Surgery, the test involves inserting very fine needles into your muscles. The needle is able to detect electrical activity in the muscle, both normal and abnormal, because it contains a microscopic electrode.
Nerve conduction velocity test
According to Johns Hopkins Medicine, the objective of a nerve conduction velocity test is to measure the speed at which electrical impulses move along your nerve. If the speed is slower than normal, it could indicate damage to the nerve.
During a nerve conduction velocity test, the doctor puts electrode patches on your skin to stimulate the nerve. The tools used for the nerve conduction velocity study contain several electrodes that both stimulate the nerve and then measure and record the response that it makes electronically.
Based on the results of both the needle EMG and the nerve conduction velocity study, a doctor can draw a conclusion about which of your nerves have sustained damage and how serious it is. The results of the testing may also help to suggest possible treatment or management of the injury.